/**
 * @module olcs.FeatureConverter
 */
import olGeomGeometry from 'ol/geom/Geometry.js';
import olStyleIcon from 'ol/style/Icon.js';
import olSourceVector from 'ol/source/Vector.js';
import olSourceCluster from 'ol/source/Cluster.js';
import { circular as olCreateCircularPolygon } from 'ol/geom/Polygon.js';
import { boundingExtent, getCenter } from 'ol/extent.js';
import olGeomSimpleGeometry from 'ol/geom/SimpleGeometry.js';
import { convertColorToCesium, olGeometryCloneTo4326, ol4326CoordinateToCesiumCartesian, ol4326CoordinateArrayToCsCartesians } from './core.js';
import olcsCoreVectorLayerCounterpart from './core/VectorLayerCounterpart.js';
import { obj, getUid, isGroundPolylinePrimitiveSupported, waitReady } from './util.js';
/**
 * @typedef {Object} ModelStyle
 * @property {Cesium.Matrix4} [debugModelMatrix]
 * @property {Cesium.ModelFromGltfOptions} cesiumOptions
 */
class FeatureConverter {
    /**
     * Concrete base class for converting from OpenLayers3 vectors to Cesium
     * primitives.
     * Extending this class is possible provided that the extending class and
     * the library are compiled together by the closure compiler.
     * @param {!Cesium.Scene} scene Cesium scene.
     * @constructor
     * @api
     */
    constructor(scene) {
        /**
         * @protected
         */
        this.scene = scene;
        /**
         * Bind once to have a unique function for using as a listener
         * @type {function(ol.source.Vector.Event)}
         * @private
         */
        this.boundOnRemoveOrClearFeatureListener_ = this.onRemoveOrClearFeature_.bind(this);
        /**
         * @type {Cesium.Cartesian3}
         * @private
         */
        this.defaultBillboardEyeOffset_ = new Cesium.Cartesian3(0, 0, 10);
    }
    /**
     * @param {ol.source.Vector.Event} evt
     * @private
     */
    onRemoveOrClearFeature_(evt) {
        const source = evt.target;
        console.assert(source instanceof olSourceVector);
        const cancellers = obj(source)['olcs_cancellers'];
        if (cancellers) {
            const feature = evt.feature;
            if (feature) {
                // remove
                const id = getUid(feature);
                const canceller = cancellers[id];
                if (canceller) {
                    canceller();
                    delete cancellers[id];
                }
            }
            else {
                // clear
                for (const key in cancellers) {
                    if (cancellers.hasOwnProperty(key)) {
                        cancellers[key]();
                    }
                }
                obj(source)['olcs_cancellers'] = {};
            }
        }
    }
    /**
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature.
     * @param {!Cesium.Primitive|Cesium.Label|Cesium.Billboard} primitive
     * @protected
     */
    setReferenceForPicking(layer, feature, primitive) {
        primitive.olLayer = layer;
        primitive.olFeature = feature;
    }
    /**
     * Basics primitive creation using a color attribute.
     * Note that Cesium has 'interior' and outline geometries.
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature.
     * @param {!ol.geom.Geometry} olGeometry OpenLayers geometry.
     * @param {!Cesium.Geometry} geometry
     * @param {!Cesium.Color} color
     * @param {number=} opt_lineWidth
     * @return {Cesium.Primitive}
     * @protected
     */
    createColoredPrimitive(layer, feature, olGeometry, geometry, color, opt_lineWidth) {
        const createInstance = function (geometry, color) {
            const instance = new Cesium.GeometryInstance({
                // always update Cesium externs before adding a property
                geometry
            });
            if (color && !(color instanceof Cesium.ImageMaterialProperty)) {
                instance.attributes = {
                    color: Cesium.ColorGeometryInstanceAttribute.fromColor(color)
                };
            }
            return instance;
        };
        const options = {
            // always update Cesium externs before adding a property
            flat: true,
            renderState: {
                depthTest: {
                    enabled: true
                }
            }
        };
        if (opt_lineWidth !== undefined) {
            if (!options.renderState) {
                options.renderState = {};
            }
            options.renderState.lineWidth = opt_lineWidth;
        }
        const instances = createInstance(geometry, color);
        const heightReference = this.getHeightReference(layer, feature, olGeometry);
        let primitive;
        if (heightReference === Cesium.HeightReference.CLAMP_TO_GROUND) {
            const ctor = instances.geometry.constructor;
            if (ctor && !ctor['createShadowVolume']) {
                return null;
            }
            primitive = new Cesium.GroundPrimitive({
                geometryInstances: instances
            });
        }
        else {
            primitive = new Cesium.Primitive({
                geometryInstances: instances
            });
        }
        if (color instanceof Cesium.ImageMaterialProperty) {
            const dataUri = color.image.getValue().toDataURL();
            primitive.appearance = new Cesium.MaterialAppearance({
                flat: true,
                renderState: {
                    depthTest: {
                        enabled: true,
                    }
                },
                material: new Cesium.Material({
                    fabric: {
                        type: 'Image',
                        uniforms: {
                            image: dataUri
                        }
                    }
                })
            });
        }
        else {
            primitive.appearance = new Cesium.MaterialAppearance({
                ...options,
                material: new Cesium.Material({
                    translucent: color.alpha !== 1,
                    fabric: {
                        type: 'Color',
                        uniforms: {
                            color,
                        }
                    }
                })
            });
            if (feature.get('olcs_shadows') || layer.get('olcs_shadows')) {
                primitive.shadows = 1;
            }
        }
        this.setReferenceForPicking(layer, feature, primitive);
        return primitive;
    }
    /**
     * Return the fill or stroke color from a plain ol style.
     * @param {!ol.style.Style|ol.style.Text} style
     * @param {boolean} outline
     * @return {!Cesium.Color}
     * @protected
     */
    extractColorFromOlStyle(style, outline) {
        const fillColor = style.getFill() ? style.getFill().getColor() : null;
        const strokeColor = style.getStroke() ? style.getStroke().getColor() : null;
        let olColor = 'black';
        if (strokeColor && outline) {
            olColor = strokeColor;
        }
        else if (fillColor) {
            olColor = fillColor;
        }
        return convertColorToCesium(olColor);
    }
    /**
     * Return the width of stroke from a plain ol style.
     * @param {!ol.style.Style|ol.style.Text} style
     * @return {number}
     * @protected
     */
    extractLineWidthFromOlStyle(style) {
        // Handling of line width WebGL limitations is handled by Cesium.
        const width = style.getStroke() ? style.getStroke().getWidth() : undefined;
        return width !== undefined ? width : 1;
    }
    /**
     * Create a primitive collection out of two Cesium geometries.
     * Only the OpenLayers style colors will be used.
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature.
     * @param {!ol.geom.Geometry} olGeometry OpenLayers geometry.
     * @param {!Cesium.Geometry} fillGeometry
     * @param {!Cesium.Geometry} outlineGeometry
     * @param {!ol.style.Style} olStyle
     * @return {!Cesium.PrimitiveCollection}
     * @protected
     */
    wrapFillAndOutlineGeometries(layer, feature, olGeometry, fillGeometry, outlineGeometry, olStyle) {
        const fillColor = this.extractColorFromOlStyle(olStyle, false);
        const outlineColor = this.extractColorFromOlStyle(olStyle, true);
        const primitives = new Cesium.PrimitiveCollection();
        if (olStyle.getFill()) {
            const p1 = this.createColoredPrimitive(layer, feature, olGeometry, fillGeometry, fillColor);
            console.assert(!!p1);
            primitives.add(p1);
        }
        if (olStyle.getStroke() && outlineGeometry) {
            const width = this.extractLineWidthFromOlStyle(olStyle);
            const p2 = this.createColoredPrimitive(layer, feature, olGeometry, outlineGeometry, outlineColor, width);
            if (p2) {
                // Some outline geometries are not supported by Cesium in clamp to ground
                // mode. These primitives are skipped.
                primitives.add(p2);
            }
        }
        return primitives;
    }
    // Geometry converters
    /**
     * Create a Cesium primitive if style has a text component.
     * Eventually return a PrimitiveCollection including current primitive.
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature..
     * @param {!ol.geom.Geometry} geometry
     * @param {!ol.style.Style} style
     * @param {!Cesium.Primitive} primitive current primitive
     * @return {!Cesium.PrimitiveCollection}
     * @protected
     */
    addTextStyle(layer, feature, geometry, style, primitive) {
        let primitives;
        if (!(primitive instanceof Cesium.PrimitiveCollection)) {
            primitives = new Cesium.PrimitiveCollection();
            primitives.add(primitive);
        }
        else {
            primitives = primitive;
        }
        if (!style.getText()) {
            return primitives;
        }
        const text = /** @type {!ol.style.Text} */ (style.getText());
        const label = this.olGeometry4326TextPartToCesium(layer, feature, geometry, text);
        if (label) {
            primitives.add(label);
        }
        return primitives;
    }
    /**
     * Add a billboard to a Cesium.BillboardCollection.
     * Overriding this wrapper allows manipulating the billboard options.
     * @param {!Cesium.BillboardCollection} billboards
     * @param {!Cesium.optionsBillboardCollectionAdd} bbOptions
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature.
     * @param {!ol.geom.Geometry} geometry
     * @param {!ol.style.Style} style
     * @return {!Cesium.Billboard} newly created billboard
     * @api
     */
    csAddBillboard(billboards, bbOptions, layer, feature, geometry, style) {
        if (!bbOptions.eyeOffset) {
            bbOptions.eyeOffset = this.defaultBillboardEyeOffset_;
        }
        const bb = billboards.add(bbOptions);
        this.setReferenceForPicking(layer, feature, bb);
        return bb;
    }
    /**
     * Convert an OpenLayers circle geometry to Cesium.
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature..
     * @param {!ol.geom.Circle} olGeometry OpenLayers circle geometry.
     * @param {!ol.ProjectionLike} projection
     * @param {!ol.style.Style} olStyle
     * @return {!Cesium.PrimitiveCollection} primitives
     * @api
     */
    olCircleGeometryToCesium(layer, feature, olGeometry, projection, olStyle) {
        olGeometry = olGeometryCloneTo4326(olGeometry, projection);
        console.assert(olGeometry.getType() == 'Circle');
        // ol.Coordinate
        let center = olGeometry.getCenter();
        const height = center.length == 3 ? center[2] : 0.0;
        let point = center.slice();
        point[0] += olGeometry.getRadius();
        // Cesium
        center = ol4326CoordinateToCesiumCartesian(center);
        point = ol4326CoordinateToCesiumCartesian(point);
        // Accurate computation of straight distance
        const radius = Cesium.Cartesian3.distance(center, point);
        const fillGeometry = new Cesium.CircleGeometry({
            // always update Cesium externs before adding a property
            center,
            radius,
            height
        });
        let outlinePrimitive, outlineGeometry;
        if (this.getHeightReference(layer, feature, olGeometry) === Cesium.HeightReference.CLAMP_TO_GROUND) {
            const width = this.extractLineWidthFromOlStyle(olStyle);
            if (width) {
                const circlePolygon = olCreateCircularPolygon(olGeometry.getCenter(), radius);
                const positions = ol4326CoordinateArrayToCsCartesians(circlePolygon.getLinearRing(0).getCoordinates());
                if (!isGroundPolylinePrimitiveSupported(this.scene)) {
                    const color = this.extractColorFromOlStyle(olStyle, true);
                    outlinePrimitive = this.createStackedGroundCorridors(layer, feature, width, color, positions);
                }
                else {
                    outlinePrimitive = new Cesium.GroundPolylinePrimitive({
                        geometryInstances: new Cesium.GeometryInstance({
                            geometry: new Cesium.GroundPolylineGeometry({ positions, width }),
                        }),
                        appearance: new Cesium.PolylineMaterialAppearance({
                            material: this.olStyleToCesium(feature, olStyle, true),
                        }),
                        classificationType: Cesium.ClassificationType.TERRAIN,
                    });
                    waitReady(outlinePrimitive).then(() => {
                        this.setReferenceForPicking(layer, feature, outlinePrimitive._primitive);
                    });
                }
            }
        }
        else {
            outlineGeometry = new Cesium.CircleOutlineGeometry({
                // always update Cesium externs before adding a property
                center,
                radius,
                extrudedHeight: height,
                height
            });
        }
        const primitives = this.wrapFillAndOutlineGeometries(layer, feature, olGeometry, fillGeometry, outlineGeometry, olStyle);
        if (outlinePrimitive) {
            primitives.add(outlinePrimitive);
        }
        return this.addTextStyle(layer, feature, olGeometry, olStyle, primitives);
    }
    /**
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature..
     * @param {!number} width The width of the line.
     * @param {!Cesium.Color} color The color of the line.
     * @param {!Array<Cesium.Cartesian3>|Array<Array<Cesium.Cartesian3>>} positions The vertices of the line(s).
     * @return {!Cesium.GroundPrimitive} primitive
     */
    createStackedGroundCorridors(layer, feature, width, color, positions) {
        // Convert positions to an Array if it isn't
        if (!Array.isArray(positions[0])) {
            positions = [positions];
        }
        width = Math.max(3, width); // A <3px width is too small for ground primitives
        const geometryInstances = [];
        let previousDistance = 0;
        // A stack of ground lines with increasing width (in meters) are created.
        // Only one of these lines is displayed at any time giving a feeling of continuity.
        // The values for the distance and width factor are more or less arbitrary.
        // Applications can override this logics by subclassing the FeatureConverter class.
        for (const distance of [1000, 4000, 16000, 64000, 254000, 1000000, 10000000]) {
            width *= 2.14;
            const geometryOptions = {
                // always update Cesium externs before adding a property
                width,
                vertexFormat: Cesium.VertexFormat.POSITION_ONLY
            };
            for (const linePositions of positions) {
                geometryOptions.positions = linePositions;
                geometryInstances.push(new Cesium.GeometryInstance({
                    geometry: new Cesium.CorridorGeometry(geometryOptions),
                    attributes: {
                        color: Cesium.ColorGeometryInstanceAttribute.fromColor(color),
                        distanceDisplayCondition: new Cesium.DistanceDisplayConditionGeometryInstanceAttribute(previousDistance, distance - 1)
                    }
                }));
            }
            previousDistance = distance;
        }
        return new Cesium.GroundPrimitive({
            // always update Cesium externs before adding a property
            geometryInstances
        });
    }
    /**
     * Convert an OpenLayers line string geometry to Cesium.
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature..
     * @param {!ol.geom.LineString} olGeometry OpenLayers line string geometry.
     * @param {!ol.ProjectionLike} projection
     * @param {!ol.style.Style} olStyle
     * @return {!Cesium.PrimitiveCollection} primitives
     * @api
     */
    olLineStringGeometryToCesium(layer, feature, olGeometry, projection, olStyle) {
        olGeometry = olGeometryCloneTo4326(olGeometry, projection);
        console.assert(olGeometry.getType() == 'LineString');
        const positions = ol4326CoordinateArrayToCsCartesians(olGeometry.getCoordinates());
        const width = this.extractLineWidthFromOlStyle(olStyle);
        let outlinePrimitive;
        const heightReference = this.getHeightReference(layer, feature, olGeometry);
        if (heightReference === Cesium.HeightReference.CLAMP_TO_GROUND && !isGroundPolylinePrimitiveSupported(this.scene)) {
            const color = this.extractColorFromOlStyle(olStyle, true);
            outlinePrimitive = this.createStackedGroundCorridors(layer, feature, width, color, positions);
        }
        else {
            const appearance = new Cesium.PolylineMaterialAppearance({
                // always update Cesium externs before adding a property
                material: this.olStyleToCesium(feature, olStyle, true)
            });
            const geometryOptions = {
                // always update Cesium externs before adding a property
                positions,
                width,
            };
            const primitiveOptions = {
                // always update Cesium externs before adding a property
                appearance
            };
            if (heightReference === Cesium.HeightReference.CLAMP_TO_GROUND) {
                const geometry = new Cesium.GroundPolylineGeometry(geometryOptions);
                primitiveOptions.geometryInstances = new Cesium.GeometryInstance({
                    geometry
                }),
                    outlinePrimitive = new Cesium.GroundPolylinePrimitive(primitiveOptions);
                waitReady(outlinePrimitive).then(() => {
                    this.setReferenceForPicking(layer, feature, outlinePrimitive._primitive);
                });
            }
            else {
                geometryOptions.vertexFormat = appearance.vertexFormat;
                const geometry = new Cesium.PolylineGeometry(geometryOptions);
                primitiveOptions.geometryInstances = new Cesium.GeometryInstance({
                    geometry
                }),
                    outlinePrimitive = new Cesium.Primitive(primitiveOptions);
            }
        }
        this.setReferenceForPicking(layer, feature, outlinePrimitive);
        return this.addTextStyle(layer, feature, olGeometry, olStyle, outlinePrimitive);
    }
    /**
     * Convert an OpenLayers polygon geometry to Cesium.
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature..
     * @param {!ol.geom.Polygon} olGeometry OpenLayers polygon geometry.
     * @param {!ol.ProjectionLike} projection
     * @param {!ol.style.Style} olStyle
     * @return {!Cesium.PrimitiveCollection} primitives
     * @api
     */
    olPolygonGeometryToCesium(layer, feature, olGeometry, projection, olStyle) {
        olGeometry = olGeometryCloneTo4326(olGeometry, projection);
        console.assert(olGeometry.getType() == 'Polygon');
        const heightReference = this.getHeightReference(layer, feature, olGeometry);
        let fillGeometry, outlineGeometry, outlinePrimitive;
        if ((olGeometry.getCoordinates()[0].length == 5) &&
            (feature.get('olcs.polygon_kind') === 'rectangle')) {
            // Create a rectangle according to the longitude and latitude curves
            const coordinates = olGeometry.getCoordinates()[0];
            // Extract the West, South, East, North coordinates
            const extent = boundingExtent(coordinates);
            const rectangle = Cesium.Rectangle.fromDegrees(extent[0], extent[1], extent[2], extent[3]);
            // Extract the average height of the vertices
            let maxHeight = 0.0;
            if (coordinates[0].length == 3) {
                for (let c = 0; c < coordinates.length; c++) {
                    maxHeight = Math.max(maxHeight, coordinates[c][2]);
                }
            }
            const featureExtrudedHeight = feature.getProperty('olcs_extruded_height');
            // Render the cartographic rectangle
            fillGeometry = new Cesium.RectangleGeometry({
                ellipsoid: Cesium.Ellipsoid.WGS84,
                rectangle,
                height: maxHeight,
                extrudedHeight: featureExtrudedHeight,
            });
            outlineGeometry = new Cesium.RectangleOutlineGeometry({
                ellipsoid: Cesium.Ellipsoid.WGS84,
                rectangle,
                height: maxHeight,
                extrudedHeight: featureExtrudedHeight,
            });
        }
        else {
            const rings = olGeometry.getLinearRings();
            // always update Cesium externs before adding a property
            const hierarchy = {};
            const polygonHierarchy = hierarchy;
            console.assert(rings.length > 0);
            for (let i = 0; i < rings.length; ++i) {
                const olPos = rings[i].getCoordinates();
                const positions = ol4326CoordinateArrayToCsCartesians(olPos);
                console.assert(positions && positions.length > 0);
                if (i == 0) {
                    hierarchy.positions = positions;
                }
                else {
                    if (!hierarchy.holes) {
                        hierarchy.holes = [];
                    }
                    hierarchy.holes.push({
                        positions
                    });
                }
            }
            const featureExtrudedHeight = feature.get('olcs_extruded_height');
            fillGeometry = new Cesium.PolygonGeometry({
                // always update Cesium externs before adding a property
                polygonHierarchy,
                perPositionHeight: true,
                extrudedHeight: featureExtrudedHeight,
            });
            // Since Cesium doesn't yet support Polygon outlines on terrain yet (coming soon...?)
            // we don't create an outline geometry if clamped, but instead do the polyline method
            // for each ring. Most of this code should be removeable when Cesium adds
            // support for Polygon outlines on terrain.
            if (heightReference === Cesium.HeightReference.CLAMP_TO_GROUND) {
                const width = this.extractLineWidthFromOlStyle(olStyle);
                if (width > 0) {
                    const positions = [hierarchy.positions];
                    if (hierarchy.holes) {
                        for (let i = 0; i < hierarchy.holes.length; ++i) {
                            positions.push(hierarchy.holes[i].positions);
                        }
                    }
                    if (!isGroundPolylinePrimitiveSupported(this.scene)) {
                        const color = this.extractColorFromOlStyle(olStyle, true);
                        outlinePrimitive = this.createStackedGroundCorridors(layer, feature, width, color, positions);
                    }
                    else {
                        const appearance = new Cesium.PolylineMaterialAppearance({
                            // always update Cesium externs before adding a property
                            material: this.olStyleToCesium(feature, olStyle, true)
                        });
                        const geometryInstances = [];
                        for (const linePositions of positions) {
                            const polylineGeometry = new Cesium.GroundPolylineGeometry({ positions: linePositions, width });
                            geometryInstances.push(new Cesium.GeometryInstance({
                                geometry: polylineGeometry
                            }));
                        }
                        const primitiveOptions = {
                            // always update Cesium externs before adding a property
                            appearance,
                            geometryInstances
                        };
                        outlinePrimitive = new Cesium.GroundPolylinePrimitive(primitiveOptions);
                        waitReady(outlinePrimitive).then(() => {
                            this.setReferenceForPicking(layer, feature, outlinePrimitive._primitive);
                        });
                    }
                }
            }
            else {
                // Actually do the normal polygon thing. This should end the removable
                // section of code described above.
                outlineGeometry = new Cesium.PolygonOutlineGeometry({
                    // always update Cesium externs before adding a property
                    polygonHierarchy: hierarchy,
                    perPositionHeight: true,
                    extrudedHeight: featureExtrudedHeight,
                });
            }
        }
        const primitives = this.wrapFillAndOutlineGeometries(layer, feature, olGeometry, fillGeometry, outlineGeometry, olStyle);
        if (outlinePrimitive) {
            primitives.add(outlinePrimitive);
        }
        return this.addTextStyle(layer, feature, olGeometry, olStyle, primitives);
    }
    /**
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {ol.Feature} feature OpenLayers feature..
     * @param {!ol.geom.Geometry} geometry
     * @return {!Cesium.HeightReference}
     * @api
     */
    getHeightReference(layer, feature, geometry) {
        // Read from the geometry
        let altitudeMode = geometry.get('altitudeMode');
        // Or from the feature
        if (altitudeMode === undefined) {
            altitudeMode = feature.get('altitudeMode');
        }
        // Or from the layer
        if (altitudeMode === undefined) {
            altitudeMode = layer.get('altitudeMode');
        }
        let heightReference = Cesium.HeightReference.NONE;
        if (altitudeMode === 'clampToGround') {
            heightReference = Cesium.HeightReference.CLAMP_TO_GROUND;
        }
        else if (altitudeMode === 'relativeToGround') {
            heightReference = Cesium.HeightReference.RELATIVE_TO_GROUND;
        }
        return heightReference;
    }
    /**
     * Convert a point geometry to a Cesium BillboardCollection.
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature..
     * @param {!ol.geom.Point} olGeometry OpenLayers point geometry.
     * @param {!ol.ProjectionLike} projection
     * @param {!ol.style.Style} style
     * @param {!ol.style.Image} imageStyle
     * @param {!Cesium.BillboardCollection} billboards
     * @param {function(!Cesium.Billboard)=} opt_newBillboardCallback Called when the new billboard is added.
     * @api
     */
    createBillboardFromImage(layer, feature, olGeometry, projection, style, imageStyle, billboards, opt_newBillboardCallback) {
        if (imageStyle instanceof olStyleIcon) {
            // make sure the image is scheduled for load
            imageStyle.load();
        }
        const image = imageStyle.getImage(1); // get normal density
        const isImageLoaded = function (image) {
            return image.src != '' &&
                image.naturalHeight != 0 &&
                image.naturalWidth != 0 &&
                image.complete;
        };
        const reallyCreateBillboard = (function () {
            if (!image) {
                return;
            }
            if (!(image instanceof HTMLCanvasElement ||
                image instanceof Image ||
                image instanceof HTMLImageElement)) {
                return;
            }
            const center = olGeometry.getCoordinates();
            const position = ol4326CoordinateToCesiumCartesian(center);
            let color;
            const opacity = imageStyle.getOpacity();
            if (opacity !== undefined) {
                color = new Cesium.Color(1.0, 1.0, 1.0, opacity);
            }
            const scale = imageStyle.getScale();
            const heightReference = this.getHeightReference(layer, feature, olGeometry);
            const bbOptions = /** @type {Cesium.optionsBillboardCollectionAdd} */ ({
                // always update Cesium externs before adding a property
                image,
                color,
                scale,
                heightReference,
                position
            });
            // merge in cesium options from openlayers feature
            Object.assign(bbOptions, feature.get('cesiumOptions'));
            if (imageStyle instanceof olStyleIcon) {
                const anchor = imageStyle.getAnchor();
                if (anchor) {
                    bbOptions.pixelOffset = new Cesium.Cartesian2((image.width / 2 - anchor[0]) * scale, (image.height / 2 - anchor[1]) * scale);
                }
            }
            const bb = this.csAddBillboard(billboards, bbOptions, layer, feature, olGeometry, style);
            if (opt_newBillboardCallback) {
                opt_newBillboardCallback(bb);
            }
        }).bind(this);
        if (image instanceof Image && !isImageLoaded(image)) {
            // Cesium requires the image to be loaded
            let cancelled = false;
            const source = layer.getSource();
            const canceller = function () {
                cancelled = true;
            };
            source.on(['removefeature', 'clear'], this.boundOnRemoveOrClearFeatureListener_);
            let cancellers = obj(source)['olcs_cancellers'];
            if (!cancellers) {
                cancellers = obj(source)['olcs_cancellers'] = {};
            }
            const fuid = getUid(feature);
            if (cancellers[fuid]) {
                // When the feature change quickly, a canceller may still be present so
                // we cancel it here to prevent creation of a billboard.
                cancellers[fuid]();
            }
            cancellers[fuid] = canceller;
            const listener = function () {
                image.removeEventListener('load', listener);
                if (!billboards.isDestroyed() && !cancelled) {
                    // Create billboard if the feature is still displayed on the map.
                    reallyCreateBillboard();
                }
            };
            image.addEventListener('load', listener);
        }
        else {
            reallyCreateBillboard();
        }
    }
    /**
     * Convert a point geometry to a Cesium BillboardCollection.
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature..
     * @param {!ol.geom.Point} olGeometry OpenLayers point geometry.
     * @param {!ol.ProjectionLike} projection
     * @param {!ol.style.Style} style
     * @param {!Cesium.BillboardCollection} billboards
     * @param {function(!Cesium.Billboard)=} opt_newBillboardCallback Called when
     * the new billboard is added.
     * @return {Cesium.Primitive} primitives
     * @api
     */
    olPointGeometryToCesium(layer, feature, olGeometry, projection, style, billboards, opt_newBillboardCallback) {
        console.assert(olGeometry.getType() == 'Point');
        olGeometry = olGeometryCloneTo4326(olGeometry, projection);
        let modelPrimitive = null;
        const imageStyle = style.getImage();
        if (imageStyle) {
            const olcsModelFunction = /** @type {function():olcsx.ModelStyle} */ (olGeometry.get('olcs_model') || feature.get('olcs_model'));
            if (olcsModelFunction) {
                modelPrimitive = new Cesium.PrimitiveCollection();
                const olcsModel = olcsModelFunction();
                const options = /** @type {Cesium.ModelFromGltfOptions} */ (Object.assign({}, { scene: this.scene }, olcsModel.cesiumOptions));
                if (Cesium.Model.fromGltf) {
                    // pre Cesium v107
                    const model = Cesium.Model.fromGltf(options);
                    modelPrimitive.add(model);
                }
                else {
                    Cesium.Model.fromGltfAsync(options).then((model) => {
                        modelPrimitive.add(model);
                    });
                }
                if (olcsModel.debugModelMatrix) {
                    modelPrimitive.add(new Cesium.DebugModelMatrixPrimitive({
                        modelMatrix: olcsModel.debugModelMatrix
                    }));
                }
            }
            else {
                this.createBillboardFromImage(layer, feature, olGeometry, projection, style, imageStyle, billboards, opt_newBillboardCallback);
            }
        }
        if (style.getText()) {
            return this.addTextStyle(layer, feature, olGeometry, style, modelPrimitive || new Cesium.Primitive());
        }
        else {
            return modelPrimitive;
        }
    }
    /**
     * Convert an OpenLayers multi-something geometry to Cesium.
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature..
     * @param {!ol.geom.Geometry} geometry OpenLayers geometry.
     * @param {!ol.ProjectionLike} projection
     * @param {!ol.style.Style} olStyle
     * @param {!Cesium.BillboardCollection} billboards
     * @param {function(!Cesium.Billboard)=} opt_newBillboardCallback Called when
     * the new billboard is added.
     * @return {Cesium.Primitive} primitives
     * @api
     */
    olMultiGeometryToCesium(layer, feature, geometry, projection, olStyle, billboards, opt_newBillboardCallback) {
        // Do not reproject to 4326 now because it will be done later.
        // FIXME: would be better to combine all child geometries in one primitive
        // instead we create n primitives for simplicity.
        const accumulate = function (geometries, functor) {
            const primitives = new Cesium.PrimitiveCollection();
            geometries.forEach((geometry) => {
                primitives.add(functor(layer, feature, geometry, projection, olStyle));
            });
            return primitives;
        };
        let subgeos;
        switch (geometry.getType()) {
            case 'MultiPoint':
                geometry = /** @type {!ol.geom.MultiPoint} */ (geometry);
                subgeos = geometry.getPoints();
                if (olStyle.getText()) {
                    const primitives = new Cesium.PrimitiveCollection();
                    subgeos.forEach((geometry) => {
                        console.assert(geometry);
                        const result = this.olPointGeometryToCesium(layer, feature, geometry, projection, olStyle, billboards, opt_newBillboardCallback);
                        if (result) {
                            primitives.add(result);
                        }
                    });
                    return primitives;
                }
                else {
                    subgeos.forEach((geometry) => {
                        console.assert(geometry);
                        this.olPointGeometryToCesium(layer, feature, geometry, projection, olStyle, billboards, opt_newBillboardCallback);
                    });
                    return null;
                }
            case 'MultiLineString':
                geometry = /** @type {!ol.geom.MultiLineString} */ (geometry);
                subgeos = geometry.getLineStrings();
                return accumulate(subgeos, this.olLineStringGeometryToCesium.bind(this));
            case 'MultiPolygon':
                geometry = /** @type {!ol.geom.MultiPolygon} */ (geometry);
                subgeos = geometry.getPolygons();
                return accumulate(subgeos, this.olPolygonGeometryToCesium.bind(this));
            default:
                console.assert(false, `Unhandled multi geometry type${geometry.getType()}`);
        }
    }
    /**
     * Convert an OpenLayers text style to Cesium.
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature..
     * @param {!ol.geom.Geometry} geometry
     * @param {!ol.style.Text} style
     * @return {Cesium.LabelCollection} Cesium primitive
     * @api
     */
    olGeometry4326TextPartToCesium(layer, feature, geometry, style) {
        const text = style.getText();
        if (!text) {
            return null;
        }
        const labels = new Cesium.LabelCollection({ scene: this.scene });
        // TODO: export and use the text draw position from OpenLayers .
        // See src/ol/render/vector.js
        const extentCenter = getCenter(geometry.getExtent());
        if (geometry instanceof olGeomSimpleGeometry) {
            const first = geometry.getFirstCoordinate();
            extentCenter[2] = first.length == 3 ? first[2] : 0.0;
        }
        const options = /** @type {Cesium.optionsLabelCollection} */ ({});
        options.position = ol4326CoordinateToCesiumCartesian(extentCenter);
        options.text = text;
        options.heightReference = this.getHeightReference(layer, feature, geometry);
        const offsetX = style.getOffsetX();
        const offsetY = style.getOffsetY();
        if (offsetX != 0 && offsetY != 0) {
            const offset = new Cesium.Cartesian2(offsetX, offsetY);
            options.pixelOffset = offset;
        }
        options.font = style.getFont() || '10px sans-serif'; // OpenLayers default
        let labelStyle = undefined;
        if (style.getFill()) {
            options.fillColor = this.extractColorFromOlStyle(style, false);
            labelStyle = Cesium.LabelStyle.FILL;
        }
        if (style.getStroke()) {
            options.outlineWidth = this.extractLineWidthFromOlStyle(style);
            options.outlineColor = this.extractColorFromOlStyle(style, true);
            labelStyle = Cesium.LabelStyle.OUTLINE;
        }
        if (style.getFill() && style.getStroke()) {
            labelStyle = Cesium.LabelStyle.FILL_AND_OUTLINE;
        }
        options.style = labelStyle;
        let horizontalOrigin;
        switch (style.getTextAlign()) {
            case 'left':
                horizontalOrigin = Cesium.HorizontalOrigin.LEFT;
                break;
            case 'right':
                horizontalOrigin = Cesium.HorizontalOrigin.RIGHT;
                break;
            case 'center':
            default:
                horizontalOrigin = Cesium.HorizontalOrigin.CENTER;
        }
        options.horizontalOrigin = horizontalOrigin;
        if (style.getTextBaseline()) {
            let verticalOrigin;
            switch (style.getTextBaseline()) {
                case 'top':
                    verticalOrigin = Cesium.VerticalOrigin.TOP;
                    break;
                case 'middle':
                    verticalOrigin = Cesium.VerticalOrigin.CENTER;
                    break;
                case 'bottom':
                    verticalOrigin = Cesium.VerticalOrigin.BOTTOM;
                    break;
                case 'alphabetic':
                    verticalOrigin = Cesium.VerticalOrigin.TOP;
                    break;
                case 'hanging':
                    verticalOrigin = Cesium.VerticalOrigin.BOTTOM;
                    break;
                default:
                    console.assert(false, `unhandled baseline ${style.getTextBaseline()}`);
            }
            options.verticalOrigin = verticalOrigin;
        }
        const l = labels.add(options);
        this.setReferenceForPicking(layer, feature, l);
        return labels;
    }
    /**
     * Convert an OpenLayers style to a Cesium Material.
     * @param {ol.Feature} feature OpenLayers feature..
     * @param {!ol.style.Style} style
     * @param {boolean} outline
     * @return {Cesium.Material}
     * @api
     */
    olStyleToCesium(feature, style, outline) {
        const fill = style.getFill();
        const stroke = style.getStroke();
        if ((outline && !stroke) || (!outline && !fill)) {
            return null; // FIXME use a default style? Developer error?
        }
        let color = outline ? stroke.getColor() : fill.getColor();
        color = convertColorToCesium(color);
        if (outline && stroke.getLineDash()) {
            return Cesium.Material.fromType('Stripe', {
                // always update Cesium externs before adding a property
                horizontal: false,
                repeat: 500,
                evenColor: color,
                oddColor: new Cesium.Color(0, 0, 0, 0) // transparent
            });
        }
        else {
            return Cesium.Material.fromType('Color', {
                // always update Cesium externs before adding a property
                color
            });
        }
    }
    /**
     * Compute OpenLayers plain style.
     * Evaluates style function, blend arrays, get default style.
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature
     * @param {ol.StyleFunction|undefined} fallbackStyleFunction
     * @param {number} resolution
     * @return {Array.<!ol.style.Style>} null if no style is available
     * @api
     */
    computePlainStyle(layer, feature, fallbackStyleFunction, resolution) {
        /**
         * @type {ol.FeatureStyleFunction|undefined}
         */
        const featureStyleFunction = feature.getStyleFunction();
        /**
         * @type {ol.style.Style|Array.<ol.style.Style>}
         */
        let style = null;
        if (featureStyleFunction) {
            style = featureStyleFunction(feature, resolution);
        }
        if (!style && fallbackStyleFunction) {
            style = fallbackStyleFunction(feature, resolution);
        }
        if (!style) {
            // The feature must not be displayed
            return null;
        }
        // FIXME combine materials as in cesium-materials-pack?
        // then this function must return a custom material
        // More simply, could blend the colors like described in
        // http://en.wikipedia.org/wiki/Alpha_compositing
        return Array.isArray(style) ? style : [style];
    }
    /**
     * @protected
     * @param {!ol.Feature} feature
     * @param {!ol.style.Style} style
     * @param {!ol.geom.Geometry=} opt_geom Geometry to be converted.
     * @return {ol.geom.Geometry|undefined}
     */
    getGeometryFromFeature(feature, style, opt_geom) {
        if (opt_geom) {
            return opt_geom;
        }
        const geom3d = /** @type {!ol.geom.Geometry} */ (feature.get('olcs.3d_geometry'));
        if (geom3d && geom3d instanceof olGeomGeometry) {
            return geom3d;
        }
        if (style) {
            const geomFuncRes = style.getGeometryFunction()(feature);
            if (geomFuncRes instanceof olGeomGeometry) {
                return geomFuncRes;
            }
        }
        return feature.getGeometry();
    }
    /**
     * Convert one OpenLayers feature up to a collection of Cesium primitives.
     * @param {ol.layer.Vector|ol.layer.Image} layer
     * @param {!ol.Feature} feature OpenLayers feature.
     * @param {!ol.style.Style} style
     * @param {!import('olcs/core/VectorLayerConterpart.js').OlFeatureToCesiumContext} context
     * @param {!ol.geom.Geometry=} opt_geom Geometry to be converted.
     * @return {Cesium.Primitive} primitives
     * @api
     */
    olFeatureToCesium(layer, feature, style, context, opt_geom) {
        let geom = this.getGeometryFromFeature(feature, style, opt_geom);
        if (!geom) {
            // OpenLayers features may not have a geometry
            // See http://geojson.org/geojson-spec.html#feature-objects
            return null;
        }
        const proj = context.projection;
        const newBillboardAddedCallback = function (bb) {
            const featureBb = context.featureToCesiumMap[getUid(feature)];
            if (featureBb instanceof Array) {
                featureBb.push(bb);
            }
            else {
                context.featureToCesiumMap[getUid(feature)] = [bb];
            }
        };
        switch (geom.getType()) {
            case 'GeometryCollection':
                const primitives = new Cesium.PrimitiveCollection();
                const collection = /** @type {!ol.geom.GeometryCollection} */ (geom);
                // TODO: use getGeometriesArray() instead
                collection.getGeometries().forEach((geom) => {
                    if (geom) {
                        const prims = this.olFeatureToCesium(layer, feature, style, context, geom);
                        if (prims) {
                            primitives.add(prims);
                        }
                    }
                });
                return primitives;
            case 'Point':
                geom = /** @type {!ol.geom.Point} */ (geom);
                const bbs = context.billboards;
                const result = this.olPointGeometryToCesium(layer, feature, geom, proj, style, bbs, newBillboardAddedCallback);
                if (!result) {
                    // no wrapping primitive
                    return null;
                }
                else {
                    return result;
                }
            case 'Circle':
                geom = /** @type {!ol.geom.Circle} */ (geom);
                return this.olCircleGeometryToCesium(layer, feature, geom, proj, style);
            case 'LineString':
                geom = /** @type {!ol.geom.LineString} */ (geom);
                return this.olLineStringGeometryToCesium(layer, feature, geom, proj, style);
            case 'Polygon':
                geom = /** @type {!ol.geom.Polygon} */ (geom);
                return this.olPolygonGeometryToCesium(layer, feature, geom, proj, style);
            case 'MultiPoint':
            case 'MultiLineString':
            case 'MultiPolygon':
                const result2 = this.olMultiGeometryToCesium(layer, feature, geom, proj, style, context.billboards, newBillboardAddedCallback);
                if (!result2) {
                    // no wrapping primitive
                    return null;
                }
                else {
                    return result2;
                }
            case 'LinearRing':
                throw new Error('LinearRing should only be part of polygon.');
            default:
                throw new Error(`Ol geom type not handled : ${geom.getType()}`);
        }
    }
    /**
     * Convert an OpenLayers vector layer to Cesium primitive collection.
     * For each feature, the associated primitive will be stored in
     * `featurePrimitiveMap`.
     * @param {!(ol.layer.Vector|ol.layer.Image)} olLayer
     * @param {!ol.View} olView
     * @param {!Object.<number, !Cesium.Primitive>} featurePrimitiveMap
     * @return {!olcs.core.VectorLayerCounterpart}
     * @api
     */
    olVectorLayerToCesium(olLayer, olView, featurePrimitiveMap) {
        const proj = olView.getProjection();
        const resolution = olView.getResolution();
        if (resolution === undefined || !proj) {
            console.assert(false, 'View not ready');
            // an assertion is not enough for closure to assume resolution and proj
            // are defined
            throw new Error('View not ready');
        }
        let source = olLayer.getSource();
        if (source instanceof olSourceCluster) {
            source = source.getSource();
        }
        console.assert(source instanceof olSourceVector);
        const features = source.getFeatures();
        const counterpart = new olcsCoreVectorLayerCounterpart(proj, this.scene);
        const context = counterpart.context;
        for (let i = 0; i < features.length; ++i) {
            const feature = features[i];
            if (!feature) {
                continue;
            }
            /**
             * @type {ol.StyleFunction|undefined}
             */
            const layerStyle = olLayer.getStyleFunction();
            const styles = this.computePlainStyle(olLayer, feature, layerStyle, resolution);
            if (!styles || !styles.length) {
                // only 'render' features with a style
                continue;
            }
            /**
             * @type {Cesium.Primitive|null}
             */
            let primitives = null;
            for (let i = 0; i < styles.length; i++) {
                const prims = this.olFeatureToCesium(olLayer, feature, styles[i], context);
                if (prims) {
                    if (!primitives) {
                        primitives = prims;
                    }
                    else if (prims) {
                        let i = 0, prim;
                        while ((prim = prims.get(i))) {
                            primitives.add(prim);
                            i++;
                        }
                    }
                }
            }
            if (!primitives) {
                continue;
            }
            featurePrimitiveMap[getUid(feature)] = primitives;
            counterpart.getRootPrimitive().add(primitives);
        }
        return counterpart;
    }
    /**
     * Convert an OpenLayers feature to Cesium primitive collection.
     * @param {!(ol.layer.Vector|ol.layer.Image)} layer
     * @param {!ol.View} view
     * @param {!ol.Feature} feature
     * @param {!import('olcs/core/VectorLayerConterpart.js').OlFeatureToCesiumContext} context
     * @return {Cesium.Primitive}
     * @api
     */
    convert(layer, view, feature, context) {
        const proj = view.getProjection();
        const resolution = view.getResolution();
        if (resolution == undefined || !proj) {
            return null;
        }
        /**
         * @type {ol.StyleFunction|undefined}
         */
        const layerStyle = layer.getStyleFunction();
        const styles = this.computePlainStyle(layer, feature, layerStyle, resolution);
        if (!styles || !styles.length) {
            // only 'render' features with a style
            return null;
        }
        context.projection = proj;
        /**
         * @type {Cesium.Primitive|null}
         */
        let primitives = null;
        for (let i = 0; i < styles.length; i++) {
            const prims = this.olFeatureToCesium(layer, feature, styles[i], context);
            if (!primitives) {
                primitives = prims;
            }
            else if (prims) {
                let i = 0, prim;
                while ((prim = prims.get(i))) {
                    primitives.add(prim);
                    i++;
                }
            }
        }
        return primitives;
    }
}
export default FeatureConverter;
